Plastic speaker baskets may be used to reduce weight and provide a low cost structure for certain speaker applications. Typically, plastic speaker baskets are molded directly over a metallic speaker shellpot, and then the rest of the speaker components are assembled in relation to the shellpot. However, the shellpot geometry often changes based on the design of the speaker assembly. Accordingly, new tooling, such as a new mold or mold detail, must be produced for each shellpot design, as well as each set of production tooling. As such, supporting multiple speaker designs can significantly increase manufacturing cost and complexity.
Some previous designs have accomplished attaching the shellpot to the plastic basket using either a twist lock design and/or using an adhesive to bond the shellpot to the plastic speaker basket. Although such designs allow the attachment of any of multiple shellpots to a common plastic basket, these designs may have insufficient durability for some applications. Further, a twisting or locking detail may lead to increased tooling complexity and manufacturing issues.
Loudspeakers convert electrical energy into sound and typically include a diaphragm, one or more magnets, a core cap, and a voice coil connected to the diaphragm and positioned in an air gap between the magnets and shellpot. The core cap can direct and concentrate a magnetic flux produced by the magnets into the air gap. When electrical energy flows into the voice coil, an induced magnetic field can be created that interacts with the magnetic flux in the air gap. The interaction between the voice coil current and the magnetic flux causes linear oscillation of the voice coil within the air gap, which moves the diaphragm in order to produce audible sound. However, the magnet structure of some loudspeakers may result in fringe magnetic fields that can increase the risk of reducing the efficiency of the loudspeaker. Magnetic flux density should be maintained across the length of the air gap for sufficient linear voice coil travel and optimal speaker performance.